Transmission, Distribution, and Renewable Energy Generation Power Equipment: Aging and Life Extension Techniques, Second Edition

678 Pages·2017·97.74 MB·English

by  Chudnovsky

Transmission, Distribution,
and Renewable Energy
Generation Power Equipment
Aging and Life Extension Techniques

Transmission, Distribution,
and Renewable Energy
Generation Power Equipment
Aging and Life Extension Techniques
Second Edition
Bella H. Chudnovsky
CRC Press
Taylor & Francis Group
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Boca Raton, FL 33487-2742
© 2017 by Taylor & Francis Group, LLC
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Contents
Preface..........................................................................................................................................xxvii
Author ...........................................................................................................................................xxix
Acronyms ......................................................................................................................................xxxi
Section i transmission and Distribution electrical equipment
Chapter 1 Electrical Contacts: Overheating, Wear, and Erosion ..................................................3
1.1 Electrical Contacts.............................................................................................3
1.1.1 Classification of Electrical Contacts ....................................................3
1.1.1.1 Make–Break Contacts ..........................................................3
1.1.1.2 Sliding or Rolling Contacts ..................................................3
1.1.1.3 Fixed Contacts ......................................................................4
1.1.1.4 Demountable (Detachable) Contacts ....................................4
1.1.2 Parameters of Electrical Contacts Affecting the Performance ............4
1.2 Electrical Resistance and Temperature Rise on Electrical Contacts ................6
1.2.1 Definition of Connector Temperature Rise ..........................................6
1.2.2 Thermal Condition Causing Connector Failure ...................................7
1.2.3 Overheating of Connectors and Detection Techniques
in Transmission and Distribution Systems ...........................................8
1.3 Wear and Wipe of Electrical Contact ................................................................9
1.3.1 Means to Increase Wear Resistance ...................................................11
1.3.1.1 Choice of Contact Material and Plating .............................11
1.3.1.2 Current, Voltage, and Frequency ........................................13
1.3.1.3 Lubrication ..........................................................................13
1.3.2 Means to Evaluate a Degree of Electrical Contact Wear ...................14
1.3.3 Effect of Wear Resistance on Life of Electrical Contacts ..................14
1.3.4 Effect of the Thickness of Plating on Wear Resistance .....................15
1.4 Wear and Erosion of Arcing Contacts .............................................................16
1.4.1 Arcing Erosion in SF Circuit Breakers .............................................17
6
1.4.2 Wear of the Contacts in HV and MV Air-Blast CBs .........................17
1.4.3 Wear of CB Contact Due to the Lack of Lubrication .........................19
1.5 Arcing Damage, Coking, and Filming of Electrical Contacts
in Transformer LTC .........................................................................................20
1.6 Control of Main and Arcing Contacts Wear ...................................................22
References ..................................................................................................................23
Chapter 2 Bolted, Plug-On, and Busbar Connections: Materials and Degradation....................25
2.1 Electric Connections Materials .......................................................................25
2.1.1 Copper and Copper Alloys Connections ............................................25
2.1.2 Aluminum and Aluminum Alloys Connections ................................25
2.1.3 Steel in Connections ...........................................................................26
2.2 Plating and Anodizing of the Conductors .......................................................26
2.3 Techniques to Join Electrical Conductors .......................................................27
v
vi Contents
2.3.1 Electrical Connections Made by Fusion ............................................27
2.3.2 Electrical Connections Made by Pressure..........................................27
2.4 Bolted Connections .........................................................................................28
2.4.1 Bolting Arrangements ........................................................................28
2.4.2 Recommended Materials and Hardware for Bolted Connections ......30
2.4.3 Aging Mechanisms of Bolted Joint ....................................................31
2.4.4 Condition and Preparation of Connection Surfaces ...........................31
2.4.4.1 Surface Preparation ............................................................32
2.4.4.2 Plating of the Joints ............................................................32
2.4.4.3 Procedures for Making Connections ..................................33
2.4.5 Effect of Pressure on the Resistance of Bolted Contact .....................34
2.4.6 Use of Belleville Washers ..................................................................34
2.4.7 Importance of Retightening of Bolted Joints .....................................35
2.4.8 Disadvantages and Degradation of Bolted Connections ....................35
2.4.9 Recommended Arrangements for Bolted Joint for Al and Cu
Busbar Conductor ...............................................................................36
2.4.10 Failures Caused by Inadequate Electrical Connections .....................37
2.5 Plug-On Electrical Connections ......................................................................37
2.6 Bus-Stab Separable Electrical Connections ....................................................38
2.7 Gas-Insulated Busbar Connections .................................................................39
2.8 Reliability of Electrical Connectors ................................................................40
2.9 National and International Standards and Specifications on Materials,
Testing, and Design of Busbars and Busways .................................................41
2.10 Electrical Connections Glossary .....................................................................42
References ..................................................................................................................48
Chapter 3 Plating of Electrical Equipment .................................................................................51
3.1 Electroplating for Contact Applications ..........................................................51
3.1.1 Silver Plating ......................................................................................51
3.1.1.1 Physical Properties of Silver Plating ..................................51
3.1.1.2 Silver Plating Thickness for Electrical Applications ..........51
3.1.1.3 Use of a Nickel Underplate for Silver Plating .....................52
3.1.1.4 Types of Silver Platings ......................................................53
3.1.2 Tin Plating ..........................................................................................53
3.1.2.1 Physical Properties of Tin Plating ......................................53
3.1.2.2 Tin Plating Thickness for Electrical Applications..............55
3.1.3 Nickel Plating .....................................................................................55
3.1.3.1 Applications of Nickel Plating in the Electrical
Industry .........................................................................55
3.1.3.2 Physical Properties and Thickness of Nickel Plating .........56
3.2 Electroless Plating ...........................................................................................57
3.2.1 Electroless Nickel (EN): Physical Properties .....................................57
3.2.1.1 Chemical Composition and Structure of EN Plating..........57
3.2.1.2 Physical Properties of EN Plating ......................................58
3.2.1.3 EN Film Thickness .............................................................58
3.2.2 EN: Corrosion Resistance ..................................................................58
3.2.3 EN: Electrical Resistivity ...................................................................59
3.3 EN as a Plating Alternative for Electrical Apparatuses in Corrosive
Atmosphere ......................................................................................................60
3.3.1 Testing of EN for Use in Electrical Applications ...............................61
Contents vii
3.3.1.1 Testing the Anticorrosion Properties of EN Plating ...........61
3.3.1.2 Testing of the Electrical Properties of EN Plating .............64
3.3.2 Field Testing of EN-Plated Electrical Equipment in
Energized Conditions .........................................................................65
3.3.2.1 Live Electrical Tests ...........................................................65
3.3.2.2 Electrical Properties of the Contactor Reconditioned
with EN Plating ..................................................................66
3.3.2.3 Precaution in Electrical Applications of EN Plating ..........68
3.4 Zinc Electroplating and Galvanization ............................................................69
3.4.1 Zinc Electroplating .............................................................................69
3.4.2 Zinc Galvanization Processes ............................................................69
3.4.2.1 Hot-Dip Galvanizing ..........................................................69
3.4.2.2 Continuous Galvanizing .....................................................70
3.4.2.3 Electrogalvanizing ..............................................................70
3.4.2.4 Process of Galvanizing .......................................................70
3.4.3 Conversion Zn Plating: Passivation with CrIII or CrVI .....................70
3.4.3.1 Corrosion Resistance ..........................................................70
3.4.3.2 Color Variability .................................................................71
3.4.3.3 Self-Healing Properties ......................................................71
3.4.3.4 Identification .......................................................................71
3.4.3.5 Cost Issue ............................................................................71
3.5 Metal Whiskers on Plating (Noncorrosive Phenomenon) ...............................71
3.5.1 Whisker Phenomenon and Characteristics .........................................71
3.5.1.1 Conditions and Characteristics of Growth .........................72
3.5.1.2 Environmental Factors ........................................................73
3.5.1.3 Historical Account of Metal Whisker Hazards ..................74
3.5.2 Tin Whisker Mitigation Techniques ...................................................74
3.5.2.1 Underplating .......................................................................74
3.5.2.2 Addition of Lead .................................................................75
3.5.2.3 Heat Treatments ..................................................................76
3.5.2.4 Hot-Dip Tin Plating ............................................................76
3.5.2.5 Thicker Tin Finish ..............................................................76
3.5.2.6 Conformal Coating .............................................................76
3.5.2.7 NonTin Plating and Coating ...............................................76
3.5.3 Tin Whiskers and the RoHS Initiative ...............................................76
3.5.3.1 Lead-Free Solders ...............................................................76
3.5.3.2 “Pure” Tin Finishes ............................................................77
3.5.4 Whisker Mitigation Levels Classification ..........................................77
3.5.5 Whiskers on Other Metal Platings .....................................................79
3.6 Plating on Aluminum ......................................................................................80
3.6.1 Use of Aluminum in Electrical Industry ............................................80
3.6.1.1 Choice of Plating ................................................................81
3.6.1.2 Difficulties with the Plating of Aluminum .........................81
3.6.2 Metals Used to Plate Aluminum ........................................................81
3.6.3 Methods for Plating on Aluminum ....................................................82
3.6.3.1 Plating Classifications .........................................................82
3.6.3.2 Pretreatment by Zincating ..................................................83
3.6.3.3 Tin Plating Techniques on Al .............................................83
3.6.4 Quality of Tin Plating on Al for Different Plating Techniques ..........84
3.6.4.1 Adhesion Test ......................................................................84
3.6.4.2 Thermal Shock Test ............................................................84
viii Contents
3.6.4.3 Plating Techniques and Adhesion of Tin Plating on Al .......84
3.6.4.4 Plating Techniques and the Quality of Tin Plating on Al .......85
3.7 Plating Standards and Glossary .......................................................................86
3.7.1 National and International Standards and Regulations on Plating .......86
3.8 Plating Glossary ..............................................................................................88
References ..................................................................................................................97
Chapter 4 Detrimental Processes and Aging of Plating ...........................................................101
4.1 Issues of Tin Plating Performance .................................................................101
4.1.1 General Precautions in Using Tin Plating ........................................101
4.1.1.1 Tin and Fretting Corrosion ...............................................101
4.1.1.2 Tin and Intermetallic Compounds ....................................102
4.1.2 Thermal Deterioration of Tin Plating on Aluminum .......................102
4.1.2.1 Accelerated Aging Study of Tin Plating ...........................102
4.1.2.2 Quality of Thermally Aged Tin Plating ...........................103
4.1.2.3 Mechanisms of Thermal Deterioration of Tin Plating
on Al .................................................................................105
4.1.2.4 Tin Plating on Aluminum as a Possible Cause of
Connection Overheating ...................................................106
4.1.3 Tin Pest .............................................................................................107
4.1.3.1 Definition of Tin Pest ........................................................107
4.1.3.2 Effects of Alloying Elements and the Environment
on Tin Pest ........................................................................107
4.1.3.3 Example of Tin Pest Failure in Electrical Connectors .....108
4.1.3.4 Impact of RoHS on Possible Tin Pest Failures .................109
4.2 Use of Underplating for Plating Longevity ...................................................110
4.2.1 Mitigating Role of Underplating ......................................................110
4.2.2 Advantages of Nickel as Underplating .............................................110
4.2.2.1 Ni Underplating Provides a Diffusion Barrier .................111
4.2.2.2 Ni Underplating Prevents the Formation of
Intermetallics ....................................................................111
4.2.2.3 Ni Underplating Improves Wear Resistance.....................111
4.2.2.4 Ni Underplating Increases Corrosion Resistance .............111
4.2.2.5 Other Advantages of Ni Underplating ..............................111
4.2.3 Recommended Thickness of Nickel Underplating ...........................112
4.3 Applications of Ni Underplating ...................................................................112
4.3.1 Use of Ni Underplating for Tin Plating on Copper ..........................112
4.3.1.1 The Formation of Ni−Sn Intermetallics ...........................113
4.3.2 Nickel Underplating as a Tin Whisker Mitigation Technique .........114
4.3.3 Ni Underplating for Tin Plating on Aluminum ................................115
4.3.3.1 Plating, Sample Preparation, and Testing Techniques ......115
4.3.3.2 Quality of the Plating and Interfaces ................................116
4.3.3.3 Formation of Ni–Sn Intermetallics ...................................117
4.3.3.4 Comparison of Aging Behavior of Sn Plating with
Ni, Bronze, or Cu Underlayer ...........................................117
4.3.4 Ni Underplating for Gold Plating .....................................................118
4.4 Galvanic Corrosion: Connections Made of Dissimilar Metals .....................119
4.4.1 Hazard: Galvanic Corrosion .............................................................119
4.4.2 Definition of Dissimilar Metals .......................................................120
4.4.3 Galvanic Corrosion of Copper-to-Aluminum Connections .............121
Contents ix
4.4.4 Protection of Copper-to-Aluminum Connections from Galvanic
Corrosion ..........................................................................................122
4.4.4.1 Plated Aluminum Connections .........................................122
4.4.4.2 Fasteners ...........................................................................123
4.4.4.3 Corrosion Protective Compound for
Copper-to-Aluminum Connections ..................................123
4.4.5 Galvanic Corrosion in Steel Connections with Aluminum
and Other Metals ..............................................................................123
4.4.6 General Precautions to Minimize Galvanic Corrosion
in Connections ..................................................................................124
4.5 Other Detrimental Processes Affecting Plating Performance ......................125
4.5.1 Intermetallic Compounds .................................................................125
4.5.1.1 Copper–Tin Intermetallic Compounds .............................125
4.5.1.2 Effects of Temperature and Time on the
Formation of Cu–Sn IMC .................................................125
4.5.1.3 Resistance of the Contacts with Tin Coating ...................126
4.5.2 Fretting Corrosion and a Means of Protection .................................127
4.5.2.1 Fretting Corrosion of Electrical Contacts .........................127
References ................................................................................................................128
Chapter 5 Electrical Equipment in a Corrosive Environment ..................................................131
5.1 Corrosion Factors in the Atmosphere ............................................................131
5.1.1 Types of Corrosive Atmospheres .....................................................131
5.1.1.1 Indoor Atmosphere ...........................................................131
5.1.1.2 Rural Atmosphere .............................................................131
5.1.1.3 Marine Atmosphere ..........................................................131
5.1.1.4 Industrial Atmosphere ......................................................132
5.1.2 Factors Affecting Atmospheric Corrosion .......................................132
5.1.2.1 Relative Humidity .............................................................132
5.1.2.2 Temperature ......................................................................133
5.1.2.3 Deposition of Aerosol Particles ........................................133
5.1.2.4 Pollutants, Corrosive Gases ..............................................134
5.1.3 Airborne Contamination in Data Centers ........................................135
5.1.4 Zinc Whiskers ..................................................................................135
5.2 Effect of Environment on Bare Metals ..........................................................136
5.2.1 Iron and Steel in Enclosures, Frames, Rails, and So Forth ..............136
5.2.2 Copper and Copper Alloys: Parts of the Conductive Path ...............137
5.2.3 Nickel and Nickel Alloys: Electrical Contacts and Plating ..............138
5.2.4 Aluminum and Aluminum Alloys in Electrical Applications .........138
5.3 Atmospheric Corrosion of Silver Plating ......................................................140
5.3.1 Silver Plating Corrosion and Tarnish ...............................................140
5.3.1.1 Sulfuric Corrosion ............................................................140
5.3.1.2 Silver Tarnish ....................................................................140
5.3.1.3 Silver Whiskers .................................................................141
5.3.2 Red-Plague Corrosion ......................................................................142
5.3.3 Underplating Corrosion ....................................................................143
5.3.4 Effect of Silver Plating Thickness and Quality on Sulfuric
Corrosion ..........................................................................................144
5.3.5 Corrosion of a Copper Bus with Flash Silver Plating ......................145
5.4 Effect of Silver Corrosion on Contact Resistance .........................................146